docs: def _from_pointer(cls, pointer, incref):
          """Wrap an existing :c:type:`cairo_t *` cdata pointer.
  
          :type incref: bool
          :param incref:
              Whether increase the :ref:`reference count <refcounting>` now.
          :return:
              A new :class:`Context` instance.
  
          """
          if pointer == ffi.NULL:
              raise ValueError('Null pointer')
          if incref:
              cairo.cairo_reference(pointer)
          self = object.__new__(cls)
          cls._init_pointer(self, pointer)
          return self